Bidirectionally flexible segmented tube



G. A. ULRICH 3,071,161

BIDIRECTIONALLY FLEXIBLE SEGMENTED TUBE Filed May 16, 1960 Jan. 1, 1963 o Rum tlllllllllllllllllillllllllllllllllllll Ill!Illllllllllllllflfllllllllllllllllll G USTAV A. ULRICH INVENTOR.

" 8; W .im awzzv ATZDRNEYS United States Patent 3 071 161 BIDIRECTIONALLY FIZEXIBLE SEGMENTED TUBE Gustav A. Ulrich, Rochester, N.Y., assignor to Bausch & Lomb Incorporated, a corporation of New York Filed May 16, 1960, Ser. No. 29,443 3 Claims. (Cl. 138120) This invention relates to an improved flexible tube for use in endoscopic instruments or the like, and, more particularly, to a flexible tube of segmented construction including one portion free to flex in one plane and a second portion for flexing in a different plane.

One object of the present invention is to provide an improved construction for a flexible tube for endoscopes or the like, of the type including two portions for flexing in mutually different planes so that it may be guided into difflcultly accessible body cavities such as the duodenum.

Other objects are: to provide an improved construction for a flexible tube of this character in which a flexing force may be transmitted through a first portion for flexing a second portion without applying undue flexing force to the first portion; to provide an improved device of this character in which mechanical control lines extend through integrally formed guideways in the walls of the individual segments, all of the segments being identical to each other, and selected ones of the lines being independent of flexing of the different portions of the tube; and in general, to provide an improved bi-directionally flexible, segmented tube which is of relatively simple and inexpensive construction, easy to manufacture and assemble, and rugged and long lasting in service.

These and other objects and advantages of the invention will become apparent in the following detailed description of a presently preferred embodiment thereof, taken in conjunction with the drawing wherein:

FIG. 1 is an elevational view, partly in section of an endoscope including a flexible tube according to the invention;

FIG. 2 is an elevational view, on an enlarged scale of a rigid guide segment, which is included in the flexible tube shown in FIG. 1, being disposed between'the tw differently flexing portions thereof;

FIG. 3 is a plan view of the rigid segment shown in FIG. 2; and

FIG. 4 is a cross sectional view taken along the line 4-4 of FIG. 1.

Briefly, the invention contemplates a segmented, articulated tube having at least two longitudinally extending portions arranged in series for flexing in mutually different planes. Tension lines for hingedly securing the segments together and for mechanically operating various difierent portions of the device, as well as for controllably flexing one of the portions of the tube extend longitudinally through the entire length of the tube in separate guideways formed integrally in the individual segments thereof. A special, spirally grooved segment is disposed between the two diflerently flexing portions of the tube for guiding the control lines along a spiral path so that the control lines may be oriented in a rotated relation in one portion with respect to the other portion of the tube.

In this way, certain ones of the control lines may be guided through the length of the tube in positions closely adjacent to the hinge axes between the segments so that flexing of the tube has substantially no effect on them.

The control lines for controllably flexing the one portion of the tube are 90 offset from the hinge connecting points in both portions, so that it might be expected that they would exert a flexing force on both of the portions of the tube. However, in this type of construction, it appears that the flexing force achieved by tensioning the flexing control lines is such that the portion of the tube immediately adjacent to the points of anchorage for the lines flexes first, and substantially one entire portion of the tube may be almost completely flexed without the application of undue flexing force on the other portion, even though the lines are tensioned through the other portion.

Referring now to the drawing, the endoscope illustrated therein includes front and rear elongated flexible portions 10 and 12, respectively, an intermediate cylindrical connector 14 disposed between the flexible portions 10 and 12, an objective assembly (not shown) at the front of the front flexible portion 10, and a control housing 16 secured at the rear of the rear flexible portion 12. The objective assembly is arranged for projecting a light image of the object, or field to be viewed upon the front face of a flexible image transmitting device such as the coherent bundle 18 of glass fibres, which is fitted within the flexible portions 10 and 12 and extends therein from the objective assembly to the control housing 16. A light image transmitted through the fiber bundle 18 may be viewed upon the rear face 20 of the bundle by any convenient viewing device (not shown) such as a low power microscope or other eyepiece.

The flexible portions 10 and 12 are made up of a. plurality of relatively short, articulated tubular segments 22 and 23, all of which are of identical construction. The segments 22 and 23 are urged towards each other by flexible tension members, or hinge lines 24, which extend along opposite sides of the flexible portions 10 and 12 and serve also to align the segments one with another. One face 26 of each segment is tapered to form a diametrically extending pivot ridge 27, which bears against the opposite face 28 of the next segment to provide a fulcrum. The hinge lines 24 extend through guideways 30 in the segment walls, passing through the pivot ridges 27 of the segments, and thereby permitting flexure of the flexible portions 10 and 12 without loss of tension and retaining force.

The segments 22 in the front flexible portion 10 are displaced from the segments 23 in the rear flexible portion 12 so that the front portion 10 flexes perpendicularly to the direction of flexure of the rear portion 12. The hinge lines 24 in the front portion 10 are also 90 displaced from their position in the rear portion 12.

In addition to the hinge lines 24, other control lines 32, 34, and 36 extend through separate guideways 38, 40, and 42 in the segment walls and are retained in the guideways by the elastomeric sheath 56. The lines 32 and 34 may be, for example, tension members for controlling the focus and angular position of the objective assembly at the front end of the front flexible portion 10. The last set of control lines 36, as shown, are flexible tension members for controllably flexing the front portion 10.

It is desirable to maintain the relative positions of the various lines 24, 32, 34, and 36 constant throughout the length of the endoscope so that all of the segments 22 and 23 may be of identical construction, thus minimizing the cost of manufacturing the instrument. Toward this end, in order to maintain the relative positions of the various lines uniform throughout the length of the endoscope, while at the same time providing for differently polarized fiexure of the front and rear portions 10 and 12 respectively, an intermediate connector 14 having spiral guideways 44, 46, 48, and 50 is disposed between the two portions 10 and 12 for positively guiding the lines 24, 32, 34, and 36 through the required 90 displacement.

The guideways 44, 46, 48 and 50 are preferably formed along the natural lines of tension between their angularly displaced entrant and exit ends, so that the lines 24, 32, 34, and 36 will have a natural tendency to remain in the guideways when grey are tensioned.

Preferably, the entrance and exit portions of each guideway are holes formed by drilling, as best shown in FIG. 2, to provide positive retention of the lines at both ends of the guideways. Intermediate portions of the guideways may be formed by milling spiral grooves between the end portions.

The lines are retained within the spiral grooves by an elastomeric sheath 56 which extends over the entire flexible portion of the endoscope.

The intermediate connector 14 thus maintains the desired angular relationship between the two flexible portions and 12 despite tension applied to the various lines 24, 32, 34, and 36, which extend through both of the portions 10 and 12, and which would tend to draw the two portions 10 and 12 into angular alignment with each other. The connector also minimizes friction against the lines 24, 32, 34, and 36, and permits overall simplification of the construction.

Various features of the illustrated endoscope, which are not described in detail herein, are described and claimed in the following co-pending applications of the same assignee:

Gilbert J. Sheldon, Ser. No. 679,566, filed August 22, 1957, entitled Flexible Tube Structures;

Gilbert J. Sheldon, Ser. No. 686,320, filed September 26,1957, entitled Optical Viewing Instrument, now Patent Number 2,975,785;

Gilbert J. Sheldon, Ser, No. 715,820, filed February 17, 1958, entitled Optical System for Endoscopes and the Like, now Patent Number 2,987,960;

Gilbert I. Sheldon, et al., Ser. No. 29,416, filed concurrently herewith, entitled Focusing Endoscope;

Gustav A. Ulrich, Ser. No. 29,255, filed concurrently herewith, entitled Holder for Camera and Viewing Device."

What is claimed is:

1. A flexible tube for an endoscope or the like comprising two elongated flexible portions arranged in series for flexure in mutually different planes, a tension line extending through both of said portions along the side walls thereof, and a guide member between said two portions, an elastomeric sheath encasing said portions and said guide member, said guide member having a spiral guideway for guiding said tension line through an angular displacement between said two portions so that when the respective portions of said line coextensive with said two flexible tube portions are oriented in a rotated relation between said flexible tube portions and said line is tensioned the twisting force exerted by said line upon the tube is resisted by said guide member and the angular displacement between said flexible tube portions remains undisturbed.

2. A flexible tube for an endoscope or the like comprising two flexible portions arranged in series for flexure in mutually dilferent planes, said portions being composed of a plurality of articulated tubular segments, all of said segments being of substantially identical construction and including longitudinally extending guideways in their walls, tension lines extending through said guideways from one of said portions to the other one thereof and lying in corresponding guideways in said two portions, and a guide member disposed between said portions, an elastomeric case receiving said member and said portions of the tube, said guide member having spiral guideways for guiding said lines through an angular displacement between said two portions, the opposite ends of said spiral guideways being aligned respectively with the corresponding longitudinal guideways of said segments of said two portions, whereby the twisting force exerted by said lines when they are tensioned is taken by said guide member without imposing substantial torsional forces between said two flexible portions.

3. A flexible tube for an endoscope or the like comprising two elongated flexible portions arranged in series for flexure in mutually difierent planes, a tension line extending through both of said portions along the side walls thereof, and a guide member between said two portions, an elastomeric sheath enclosing said member and said portions of said tube, said guide member having a spiral guideway for guiding said tension line through an angular displacement between said two portions so that when the respective portions of said line coextensive with said two flexible tube portions are oriented in a rotated relation between said flexible tube portions and said line is tensioned the twisting force exerted by said line upon the tube is resisted by said guide memher and the angular displacement between said flexible tube portions remains undisturbed, said spiral guideway including tubular end portions and an'outwardly opening groove portion intermediate said end portions, said groove portion extending along the natural line of tension between said end portions.

References Cited in the file of this patent UNITED STATES PATENTS 809,977 OBrien Jan. 16, 1906 1,143,824 Haese June 22, 1915 1,340,818 Brinkman May 18, 1920 2,975,785 Sheldon Mar. 21, 1961 

1. A FLEXIBLE TUBE FOR AN ENDOSCOPE OR THE LIKE COMPRISING TWO ELONGATED FLEXIBLE PORTIONS ARRANGED IN SERIES FOR FLEXTURE IN MUTUALLY DIFFERENT PLANES, A TENSION LINE EXTENDING THROUGH BOTH OF SAID PORTIONS ALONG THE SIDE WALLS THEREOF, AND A GUIDE MEMBER BETWEEN SAID TWO PORTIONS, AN ELASTOMERIC SHEATH ENCASING SAID PORTIONS AND SAID GUIDE MEMBER, SAID GUIDE MEMBER HAVING A SPIRAL GUIDEWAY FOR GUIDING SAID TENSION LINE THROUGH AN ANGULAR DISPLACEMENT BETWEEN SAID TWO PORTIONS SO THAT WHEN THE RESPECTIVE PORTIONS OF SAID LINE COEXTENSIVE WITH SAID TWO FLEXIBLE TUBE PORTIONS ARE ORIENTED IN A ROTATED RELATION BETWEEN SAID FLEXIBLE TUBE PORTIONS AND SAID LINE IS TENSIONED THE TWISTING FORCE EXERTED BY SAID LINE UPON THE TUBE IS RESISTED BY SAID GUIDE MEMBER AND THE ANGULAR DISPLACEMENT BETWEEN SAID FLEXIBLE TUBE PORTIONS REMAINS UNDISTURBED. 